1. Field of the Invention
The invention relates to critical care medical devices, and, more specifically, to a patient ventilator integrated with state-of-the-art commercial-off-the-shelf (COTS) physiologic sensors and a digitally controlled feedback system for automated monitoring and regulation for use by the first responder to provide on-scene critical life-saving support through more advanced levels of care during the crucial minutes after an injury and during evacuation.
2. Description of the Related Art
Doctrinal shifts that have occurred in the U.S. military since the end of the Cold War place greater reliance on rapidly deployable, mobile, small footprint, advanced medical resuscitation capabilities that can be moved with forces deployed on the battlefield in a time frame consistent with life-saving capabilities. The emphasis is to empower and enhance the combat medic's performance in the early minutes after acute traumatic injury, where medical intervention is most valuable in reversing a potentially fatal condition.
Data, particularly from the American experience in Vietnam, suggests that the largest battlefield mortality rates occur in the prehospital environment where no physicians are present during the early minutes after injury. Furthermore, the data leads to the conclusion that the most effective response to this aspect of the battlefield scenario is to empower medics with technological capabilities that can restore circulation, stem hemorrhage, and maintain an adequate respiratory function and oxygen delivery in acutely injured patients. This coupled with the realization that U.S. forces will be deployed in small units for short-term police actions and battle scenarios, where distances and travel may be extensive, mitigates against rapid removal and transport of heavy, weight-intensive medical equipment and supplies.
While ventilators and/or resuscitators are well known in the art, these devices have been primarily developed for use in hospitals. Thus, such devices are typically fairly cumbersome, utilize the hospital oxygen supply system, and are typically plugged into an alternating current outlet in the hospital. These typical devices are neither self-contained nor portable and, therefore, are unsuitable for battlefield use.
While some portable ventilators have been known in the past, many of these devices typically used bottled oxygen, which has an adverse oxygen supply to weight ratio. In addition, devices which rely on bottled oxygen typically have a relatively short shelf life when compared to devices which rely on chemical oxygen generators.
U.S. Pat. No. 4,651,731 to Vicenzi et at discloses a portable apparatus which is a completely self-contained portable single patient ventilator/resuscitator which utilizes a solid state oxygen generator in the form of a chlorate candle. Several adjustable features and various modes of ventilation are provided on Vicenzi's device and thus the patented apparatus is required to be used by persons with respiratory training. Vicenzi's device uses a pneumatic system to control the valves, and the valving system does not allow for selection between delivery of pure oxygen through to a mixture containing significantly less O2. The oxygen generator is used only to deliver oxygen.
U.S. Pat. No. 4,905,688 to Vicenzi et at discloses a similar portable apparatus which is a completely self-contained portable single patient ventilator/resuscitator which utilizes a solid state oxygen generator in the form of a chlorate candle. Vicenzi's device has less adjustable features and modes of ventilation, thus making it less expensive, less complex, and usable by persons with minimal training. The discussion above relating to U.S. Pat. No. 4,651,731 on the valve system, valve control, and the oxygen generator applies here.
There remains a need for small, lightweight, portable life resuscitation platforms with a long shelf life that can be carried with the troops and used by combat medics. The device must be simple to operate and provide life-sustaining support for the most common battle injuries encountered in modern combat.
More specifically, the unit should support injuries such as respiratory failure and paralysis from tension pneumothorax, hemorrhage, noxis, pulmonary damage due to pulmonary exposures, respiratory inhalation exposures, burn injuries, chemical or biological weapon injuries, and acute ventalthoric control for any other respiratory failure that may occur or be related to sedation, anesthesia or shock. The instrument must be easily resupplied or disposable and all of the capabilities necessary to operate this device must be self-contained within the device. Among these assumed capabilities are suction, monitoring, and ventilatory settings that will permit the medic to operate one device or several devices simultaneously.
Many have attempted to apply technology to the aid station/field hospital arena without a measurable decrease in mortality. The goal of any new device is to be a first rate responder system for the battlefield that will reduce pre-hospital mortality rates.